The credit-reporting and marketing giant laid out $324 million to nab 41st Parameter, a security and fraud-detection business that guards against unauthorized purchases, among other things. Importantly, 41st Parameter also runs an ad-tracking brand, AdTruth, that hawks the same basic software but for a different purpose and under a different brand identity.

In its deal announcement today, Experian chose to focus on the security business – calling out 41st Parameter's adoption by financial, retail and travel customers. But the ad opportunity is significant and clearly connected to Experian's targeted marketing business.

AdTruth lets exchanges and other ad-tech players identify users across platforms and devices by connecting those devices to a user ID. Close to 70 clients license the technology to augment or replace the cookie where needed. Those customers include OpenX, PubMatic and AdForm. The company also has been fairly aggressive on the privacy issue, engaging with the Federal Trade Commission, TRUSTe and the Digital Advertising Alliance.

41st Parameter's license agreements typically span two to three years, and renewal rates surpass 95%, Experian noted in an investor release. Its two-year compounded growth rate is 40% and the company is on a $26 million run rate for 2013. It's not clear how much of that revenue comes from security/fraud business and how much from AdTruth.

A source close to Experian said the company will market 41st Parameter's AdTruth product through its enterprise marketing group, while the cybersecurity offering will be part of a business unit within its decision analytics group.

"Experian believes there is considerable opportunity to drive adoption rates of 41st Parameter’s products through cross-selling to Experian’s existing client base, by leveraging Experian’s wide geographic footprint and through the combination of device identification into Experian’s existing identity-management products," the company said in a statement.